Type-writing machine.



L. R. ROBERTS.

TYPE WRITING MACHINE.

APPucmon man rsa. la. 19u.

Patented Mayz, 1916.

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STATES PATENT oFFicE.

LYMAN B. ROBERTS, 0F BUTHERFORD, NEW JERSEY, ASSIGNOR T0 UNDERWOOD TYPE- WRITEB COMPANY, 0F NEW YORK, N. Y., A CORPORATION 0F DELAWARE.

TYPE-WRITING MACHINE.

Speoioation of Letters Patent.

Application led February 18, 1814. Serial No. 819,840.

To all whom it may concern Be it known that I, LYMAN R. RoBERTs,.a citizen of the United States, residing 1n Rutherford, in the county of-Bergen and State of New Jersey, have invented certain new and useful Improvements in Type-Writing Machines, of which the following is a specification.,

This invention relates to platens for typewriting machines and the object of my improvement is to so construct a platen that while preserving the usual functional characteristics embraced therein, I very considerably reduce the noise produced by the impact of type thereon. In carrying out this object I provide a core of wood or other suitable rigid material, and place upon said core a series of cylindrical sections of a soft or yielding material, such for example as spongy rubber, filling the length of the core with these sections, excepting for short intervals or spaces between said sections, which are occupied with disks of equal diameter composed of felt, said disks serving as separators for 'said sections, but also serving the more importantfunction of forming interior bridgements or supports for the outer cylinf drical shell which incloses the said members and furnishes the impression supporting surface. As is usual, the outer cylindrical shell is vulcanized to a degree of semi-hardness, in order that it may aid in the production of sharp and clearly defined type impressions, but at the same time to be of not so rigid or dense a character as to prevent its cooperation with its interior filling, which is designed to influence the platen in minimizing the production of sound therefrom.

=The spaced disks of felt are suflicientlyA rigid to enable them to maintain the true cylindrical contour of the outer shell, and' occur at intervals sufliciently far apart to contain between them soft filling cushions of suitable length. The disks are preferably of felt that has been compressed in order to give it the desired stiffness, and said disks and soft sections, as strung along the core within the outer cylinder, are compacted therein between the usual end plates that the peripheral surfaces of said soft sections may be expanded into close contacting association with y the interior surface of the outer cylinder in is a similar View of one of the felt disks or bridgements.

In Fig. l of the drawing a portion of the platen frame of an Underwood typewriting machine is shown at 1, said frame carrying bearings 2 in which a shaft 3 is mounted, passing through bearings 4 on end plates 5 of a platen (the plate and bearings only'at one end of the platen being shown). The shaft 3 penetrates a cylindrical core 6 of wood or other suitable material as an interior mount, which is secured to its opposite end plates 5 centrally thereof, as by screws 5, the central orifice extending through said core being of somewhat larger diameter than shaft 3 to provide a clearance therebetween. The shaft and end plates are united by set screws passing through the bearings 4 and impinging against shaft 3.

Placed about the core 6.in alternate order are the short cylindrical sections 7 and the interposed disks 8, said sections and disks fitting snugly along the surface of co-re 6, and at their peripheral surfaces fitting snugly within the cylinder 9, of semi-hard rubber, which comprises the type impacting surface portion of the platen.

The sections 7 are intended to be of a material capable of absorbing or deadening the sound vibrations created in the outer cylindrical or surface bearing portion of the platen, and I have found the material known as spongy rubber to be eminently suitable for the purpose. This or a like material however is not possessed of suflicient distensive power to enable it to serve as a capable support for the outer cylindrical shell of semi-hard rubber, which latter, after continued service, is liable to become encaved due to lack of interior support. Therefore I provide the separating disks 8 which are preferably of compressed felt to have a requisite degree of stiffness and rigidity, and they`"are placed apart, between the opposed ends of adjacent sections 7, in order that, by their greater degrees of stiffness and rif in retaining its contour. The sound absorbing quality of felt is also appreciable in this connection, enabling the supporting disks 8 to not detract materially from the quieting influence upon the platen exercised by the spongy rubber sections.

Variations may be resorted to within the scope of the invention, and portions of the im rovements may be used without others.

aving thus described my invention, I claim:

1. An impact receiving, sound absorbing roller having a core of hard material, a peripheral portion of semi-hard material, an intermediate filling of vsoft material, and longitudinally spaced bridgements of fibrous, non-resonant material between said core and peripheral portion, said bridgements arranged at short intervals along the-roller to provide a firm backing for said peripheral portion. a

2. An impact receiving, sound absorbing roller having a core of wood, a cylindrical shell of semi-hard rubber, an intermediate filling of spongy rubber compacted between the core and shell, and longitudinally spaced bridgements of stiff felt between said core and shell,- said bridgements arranged at short intervals along the roller and providing a firm backing for the shell to receive the impact of types striking against the shell.

3. A sound-diminishing platen for typewriting machines comprising a cylindrical envelop of usual type-lmpact-receivin material, a core of solid material, a series of tubular sections of soft, porous, elastic vibrationabsorbing material ranged along said core and compacted between said envelop. and core, and disks of stiff material also ranged at frequent intervals along said core, separating said tubular sections, and serving as a firm backing for said envelop, for receiving the impact of types striking against the platen.

4. A sound-diminishing platen for typewriting machines comprlsing a cylindrical envelop of usual type-impact-recelving material, a core of solid material, a series of tubular sections-of soft, orous, elastic. vibration-absorbing material ranged along said core and compacted between said envelop and core, disks of stiff material also ranged along said core, to separate said tubular sections and serve as spaced supports for said envelop, said disks providing a firm backing for the said envelop to receive the tions, respectively of relatively soft, porous,

elastic material and stiff fibrous material, ranged alon said core in end contacting relation, sai soft sections being longer than said stiff sections and compacted by the stiff' sections between the core and cylinder, said stili sections being at short intervals along the platen and providing a firm backing for the cylinder, said soft and stiff sections unitedly filling the space between said cylinder and core, and end plates secured to said platen, to hold said sections juxtaposed within said cylinder.

6. The combination, with a typewriter carriage having bearings, of a shaft journaled therein and a platen body mounted on said shaft, said platen body comprising a core portion, an outer shell providing a surface for types to strike against, soft, porous, elastic vibration-absorbing material in the space between said shell and core, and 1ongitudinally-spaced supporting bridgements of stili, fibrous material forming a backing for said surface.

7. The combination, with a typewriter carriage having bearings, of a shaft journaled therein and a platen having end plates with bearings by which it is mounted on said shaft, said platen having a solid core to which said end plates are secured and an outer shell spaced therefrom and providing the usual impression-impact-receiving platen surface, vibration-absorbing material in said space, and longitudinally-spaced supporting bridgements between the core and shell, said bridgementsforming a firm backing for the platen surface to receive the impact of types striking against the platen.

LYMAN R. ROBERTS.

Witnesses:

LORENZ L. Parrzr.` F. E. ALEXANDER. 

